Throwable chemiluminescent device suitable for impact activation

ABSTRACT

One embodiment of a chemiluminescent device, suitable for impact activation, has the external form of a spherical tube structure with a length to width ratio of 0.5:1 to 3:1 and an internal brittle ampoule floating freely within an external tough shell. This form of the chemiluminescent device is very suitable for use in throwing, especially for fixed point throwing and limited space throwing.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of Chinese Patent Application No.200720097116.7, filed Aug. 16, 2007, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The application relates to a chemiluminescent device suitable for impactactivation and for use in throwing.

TECHNICAL BACKGROUND

Chemiluminescence is a phenomenon in which light is generated andemitted by the chemical reaction of substances.

The traditional chemiluminescent device is a thin long stick or tube,commonly known as a “light stick.” More recently, a variety of suchproducts with different shapes, including a disk shape, have been made.

The traditional chemiluminescent device has a flexible external shell inthe form of a tube. In storage, the tube contains two liquid componentsseparated from each other by a fragile barrier, a typical example ofwhich is a glass ampoule in the form of an inner tube. Whenchemiluminescence in the chemiluminescent device is required, the glassampoule is broken by snapping, and the separated chemical components inthe device mix and react to generate chemiluminescence. Typically theampoule is broken by bending the flexible tube with pressure until theampoule snaps, then the tube is shaken to mix the components inside toproduce chemiluminescence.

However, in certain activities, it may be desired to throw anunactivated chemiluminescent device to a target area at a distance, insuch a way that the chemiluminescent device is activated through theimpact of hitting the ground or other hard surface to generate light.Under such circumstances, the chemiluminescent device cannot beactivated by the traditional method of snapping the tube for activation.The current light stick, owing to the limitations of its structure,needs to be quite long in order to be reliably activated by impact. Suchproducts are currently marketed with a length reaching 380 mm (15inches). However, such length will adversely affect the use of thedevice in throwing, for example, such a long stick is not suitable forfixed point throwing, and is also inconvenient for throwing in a limitedspace.

SUMMARY OF THE INVENTION

According to one embodiment of the invention, there is provided achemiluminescent device suitable for impact activation and for use inthrowing. It has an external form different from the traditionalchemiluminescent stick, beneficial for use in throwing to a target areaat a certain distance for activation; additionally this external form isalso beneficial for throwing in a limited space.

According to one embodiment of the invention, there is provided achemiluminescent device suitable for impact activation and for use inthrowing, having an external form adopting a spherical tube structure.The external form of the chemiluminescent device adopting a sphericaltube structure mentioned above may be of a cylindrical, oblong, orpolygonal shape with the “length to diameter ratio” lying between 0.5:1and 3:1. Such a shape can give the device good throwing mechanics.

The glass used as separation material for the ampoule within thechemiluminescent device suitable for impact activation and for use inthrowing mentioned above can be made into shapes that are able to befitted into the external shell which includes spherical, oblong andcylindrical shapes.

One embodiment of a chemiluminescent device suitable for impactactivation and use for throwing has an external shell of high polymermaterial, such as polyethylene, polypropylene, polyester, etc.

The advantages made possible by embodiments of the devices described inthe present application include the following: the traditionalchemiluminescent stick usually has to be snapped by hand for activation.Even if the traditional chemiluminescent stick can be impact activatedand used for throwing, it has to have a sufficient length to facilitateactivation, thus detracting from its throwability. Chemiluminescentdevices described in the present application can have an external shellthat is very suitable for use in throwing, and that is very advantageousfor fixed point throwing and throwing in a limited space.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the presentinvention will be more apparent from the following more particulardescription thereof, presented in conjunction with the followingdrawings wherein:

FIG. 1 is a cross section of a chemiluminescent device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the accompanying drawings, one example of achemiluminescent device according to an embodiment of the presentinvention is indicated generally by the reference number 10. The device10 comprises an outer shell 12. As shown in FIG. 1, the shell 12comprises two hemispheres or half shells 14 and 16, made ofpolypropylene or other suitable material, such as high polymerpolyethylene or polyester, welded together at 18. The outer shell 12 isof generally spherical tubular form, and may be, for example, spherical,oblate or prolate spheroidal or other oblong, polygonal (prismatic orpolyhedral), or cylindrical. The length or maximum dimension of theshell 12 may be from about 0.5 to about 3 times the width, diameter, orminimum dimension of the shell 12. The shell 12 may be of a convenientsize to be held in the hand of a person intending to throw the device.For example, a device about 3 or 4 inches (7 to 10 cm) across may besuitable for many purposes.

Inside the outer shell 12 is an inner shell that in the device 10 shownin FIG. 1 is in the form of a sealed thin-walled hollow ball 20 of glassor other brittle material. As shown in FIG. 1, the ball 20 has a blowmolding orifice 22. The orifice 22 may be used for filling of the glassball 20 and then sealed.

The glass ball 20 and the space between the outer shell 12 and the glassball are partially filled with two liquids 24 and 26 that react toproduce light when they are mixed. The liquids may be liquids that arealready known as a two-component chemiluminescent system. Traditionalchemiluminescent systems use components that are low-viscosity liquids,so that they can be easily mixed by shaking, and that are reasonablystable until they are mixed.

The outer shell 12 is desirably sufficiently stiff and rigid that theshell does not distort appreciably in normal storage and handling andeven when being thrown, thereby preventing crushing of the inner ball20. The inner ball 20 is sufficiently brittle to shatter during impactonto a hard surface when thrown. The cushioning provided by the outershell 12 and the liquid 26 may reduce the impact loads on the inner balland may call for a thinner or more brittle ball than would otherwise beappropriate. The person of ordinary skill in the art will have nodifficulty in selecting the materials and thicknesses for the inner ball20 and the outer shell 12. For the inner ball 20 of the device shown inFIG. 1, a ball of ordinary glass with a thickness of 0.8 mm or less atthe thinnest part of the ball has been found to be satisfactory. Factorsto be taken into consideration include the size and intended use of thedevice 10, the composition and amount of the liquids 24 and 26. Aprincipal objective is to produce the correct balance between robustnessin storage and handling and reliable shattering of the inner ball 20 onimpact.

As shown in FIG. 1, the outer shell 12 and the inner ball 20 are onlypartially filled. The incomplete filling may impair the throwingcharacteristics of the device, by allowing the weight of the liquid tobe unevenly distributed or to move around, but for a device intended tobe thrown by hand the advantages of an incompletely filled device forimpact activation are believed to outweigh any reduction in theballistic properties. The ratio of the volume within the inner ball 20to the volume between the outer shell 12 and the inner ball 20 may be inthe range of from 10:1 to 1:10.

In use, a person takes the chemiluminescent device 10 and throws thedevice against a hard surface. When there is an impact, the outer shell12 will experience a slight change in shape, regardless of its strength.The inner ball 20 is floating loose within the outer shell. Withoutwishing to be limited to a specific theory, it is believed that when thedevice 10 hits a hard surface, the speed of the outer shell 12 dropsrapidly to zero. However, the inner ball 20, experiencing littleresistance from the low-viscosity liquid surrounding it, continues tomove quickly. The inner ball 20 eventually runs into the outer shell 12and breaks. Continued movement of the liquid components 24, 26 afterimpact causes the two liquids become mixed, and chemiluminescence isgenerated.

The outer shell 12 is made of a plastic that is tougher than the innerball 20 of glass. As in a traditional chemiluminescent light stick, theouter shell 12 does not break when the inner ball 20 breaks. The outershell 12 thus contains the chemiluminescent mixed liquid, ensuring acompact, bright, light and preventing contamination of the surroundingsby the liquid. The outer shell 12 also contains the fragments of theball 20, avoiding the risk of injury if the fragments are sharp.

Although it might seem in theory that (especially if the densities ofthe two liquids 24, 26 are similar) the outer liquid 26 will support theinner ball 20, in practice that has not been found to be a problem. Inparticular if, as shown in FIG. 1, the level of liquid 24 in the innerball 20 is higher than the level of liquid 26 in the outer shell 12, theinner ball 20 will tend to sink to the bottom of the outer shell 12. Inthat case, when the outer shell 12 is abruptly stopped by impact with ahard surface, the inner ball 20 will tend to continue moving until itstrikes the part of the outer shell that is against the hard surface.Conversely, when the device 10 is thrown, the acceleration of the outershell 12 typically results in the rear of the outer shell striking theinner ball 20. If the level of liquid 24 in the inner ball 20 is lowerthan the level of liquid 26 in the outer shell 12, the inner ball willtend to float in the outer liquid 26, and to experience contrecoupimpacts with the opposite side of the shell 12.

In any case, however, the acceleration when the device 10 is thrown byhand is less than the deceleration when the device hits a hard surface.It is thus possible to select the robustness of the inner ball 20 sothat the device 10 will reliably activate on impact with a hard surfaceat the target, but will reliably not activate on throwing.Non-activation of the device 10 on throwing is important in some gamesto avoid revealing the location of the thrower, and in many other usesfor esthetic or dramatic effect.

The device 10 may be so constructed that the inner shell or ball 20 willbreak, permitting the two liquids to mix, if the device is dropped ontoa flat hard surface from a height of 2 meters, but not if dropped from alesser height, and the outer shell 12 will not break if the device isdropped onto a flat hard surface from a height of 10 meters.

Although specific embodiments have been described, the skilled readerwill understand how features of different embodiments may be combinedand substituted, and such combinations are within the scope of thepresent invention.

1. A chemiluminescent device suitable for impact activation and use forthrowing, comprising: a tough outer shell having a maximum dimension ofat most about 3 times its minimum dimension; a brittle inner shellsmaller than the outer shell and free to move within the outer shell; afirst liquid within the inner shell; and a second liquid between theouter and inner shells, wherein the first and second liquids react toproduce light when mixed; wherein the device is so constructed that theinner shell can be caused to break, permitting the two liquids to mix,without the outer shell breaking, by impact with a flat hard surface. 2.A chemiluminescent device according to claim 1, wherein the interiorsurface of the outer shell is everywhere concave.
 3. A chemiluminescentdevice according to claim 1, wherein the inner and outer shells are sodimensioned that the volume of the space within the inner shell and thevolume of the space between the inner and outer shells are in a ratiobetween about 1:10 and about 10:1.
 4. A chemiluminescent deviceaccording to claim 1, wherein at least one of the inner and outer shellshas a volume greater than the volume of liquid it contains, so as topermit free movement of the liquid within the shell.
 5. Achemiluminescent device according to claim 1, wherein the outer shell isspherical, spheroidal, polygonal, cylindrical, or oblong.
 6. Achemiluminescent device according to claim 1, wherein the outer shellhas a longitudinal axis, and has a ratio of length along the axis todiameter perpendicular to the axis between 0.5 and 3.0.
 7. Achemilumninescent device suitable for impact activation and use forthrowing, comprising: a tough outer shell having a maximum dimension ofat most about 3 times its minimum dimension; a brittle inner shell freeto move within the outer shell; a first liquid within the inner shell;and a second liquid between the outer and inner shells, wherein thefirst and second liquids react to produce light when mixed; wherein thedevice is so constructed that the inner shell will break, permitting thetwo liquids to mix, if the device is dropped onto a flat hard surfacefrom a height of two meters and the outer shell will not break if thedevice is dropped onto a flat hard surface from a height of ten meters.8. A chemiluminescent device according to claim 7, wherein the innershell is spaced from the outer shell and free to move within the outershell.
 9. A chemiluminescent device according to claim 7, wherein theinterior surface of the outer shell is everywhere concave.
 10. Achemiluminescent device according to claim 7, wherein the inner andouter shells are so dimensioned that the volume of the space within theinner shell and the volume of the space between the inner and outershells are in a ratio between about 1:10 and about 10:1.
 11. Achemiluminescent device according to claim 7, wherein at least one ofthe inner and outer shells has a volume greater than the volume ofliquid it contains, so as to permit free movement of the liquid withinthe shell.
 12. A chemiluminescent device according to claim 7, whereinthe outer shell is spherical, spheroidal, polygonal, cylindrical, oroblong.
 13. A chemiluminescent device according to claim 7, wherein theouter shell has a longitudinal axis, and has a ratio of length along theaxis to diameter perpendicular to the axis between 0.5 and 3.0.
 14. Achemiluminescent device suitable for impact activation and use forthrowing, comprising: a tough outer shell having a maximum dimension ofat most about 3 times its minimum dimension; a brittle inner shell freeto move within the outer shell; a first liquid occupying a first chamberwithin the inner shell; and a second liquid occupying a second chamberbetween the outer and inner shells, wherein the first and second liquidsreact to produce light when mixed; wherein at least one of the first andsecond liquids only partially fills its respective chamber; wherein thedevice is so constructed that the inner shell can be caused break,permitting the two liquids to mix, without the outer shell breaking, byimpact with a flat hard surface.
 15. A chemiluminescent device accordingto claim 14, wherein the interior surface of the outer shell iseverywhere concave.
 16. A chemiluminescent device according to claim 14,wherein the inner and outer shells are so dimensioned that the volume ofthe space within the inner shell and the volume of the space between theinner and outer shells are in a ratio between about 1:10 and about 10:1.17. A chemiluminescent device according to claim 14, wherein at leastone of the inner and outer shells has a volume greater than the volumeof liquid it contains, so as to permit free movement of the liquidwithin the shell.
 18. A chemiluminescent device according to claim 14,wherein the outer shell is spherical, spheroidal, polygonal,cylindrical, or oblong.